This invention relates to a non-contact, magnetically-coupled communication technique, and particularly to an improved method and system of communication for a non-contact IC card.
Communication of data between a non-contact IC card and a data reader/writer (or a host system), such as a host computer or an IC card reader/writer (will be termed simply "reader/writer" hereinafter), takes place through the provision of a transmission circuit and a reception circuit on both sides of the data reader/writer and the IC card.
In case of communication by non-contact, electromagnetic coupling between the IC card and the reader/writer, the transmission circuits on both sides need to have a carrier generating circuit for producing a signal transmission carrier wave. Thus, the circuit is considerably complex. Therefore, it is difficult to make the circuit more compact and make the card thinner.